OBJECTIVE: To report the results from participating laboratories for four external quality control proficiency tests of dengue serological diagnosis that were carried out in the Region of the Americas in the period of 1996-2001. METHODS: External quality control proficiency tests of dengue serological diagnosis were carried out in 1996-1997, 1998-1999, 1999-2000, and 2000-2001. Panels made up of 20 serum samples (12 of them positive for dengue IgM antibodies) were sent to participating laboratories in the Region. The sera were negative for HIV antibodies, hepatitis C virus antibodies, and hepatitis B surface antigen. The sera were stored at -20 °C until they were sent in refrigerated shipments to the participating laboratories. The presence of IgM antibodies was determined through IgM-capture enzyme-linked immunosorbent assay (ELISA), while the IgG antibody titer was determined by hemagglutination inhibition or by IgG ELISA. The results of the IgM antibody testing that differed from those of the reference center were considered discordant. The IgG antibody titer was considered discordant when the results differed by two dilutions or more with respect to the reference center's results. RESULTS: A total of 27 laboratories received a total of 59 serum panels over the 1996- 2001 period, and the results from testing 54 of those panels (91.5%) were sent back in. Of the total of 1 080 sera samples from those 54 panels, the results from 95.6% of the IgM antibody tests were concordant with the results from the reference center. With 47 of the 54 panels (87.0%) the participating laboratories' agreement with the reference center's results for the IgM antibody testing was 90.0% or higher. The laboratories sent back results from a total of 27 IgG antibody titer tests, and 22 of them (81.5%) coincided with those from the reference center. Considering the IgM antibody testing results from the four periods, the findings from 22 of the participating laboratories coincided with those from the reference center for at least 90% of the samples, and 13 of the laboratories were in complete concordance with the reference center. CONCLUSIONS: The majority of the participating laboratories showed an excellent level of performance in detecting dengue IgG and IgM antibodies. However, the deficiencies found in some instances confirm the need for continuing to improve laboratory diagnosis of dengue in the Region of the Americas.

OBJECTIVE: To determine the epidemiology of Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae invasive infections in hospitalized Guatemalan children. This is an important issue since Hib vaccine has not been incorporated into the routine immunization program in Guatemala and information from hospital records in 1995 indicated a low incidence of Hib and S. pneumoniae as causes of meningitis and invasive infections. METHODS: Children who were hospitalized in Guatemala City with clinical signs compatible with bacterial infections were evaluated for evidence of Hib or S. pneumoniae infection. Normally sterile body fluids were cultured, and antigen detection was performed on cerebrospinal fluid (CSF) and pleural fluid. RESULTS: Of 1 203 children 1-59 months of age hospitalized over a 28-month period, 725 of them (60.3%) had a primary diagnosis of pneumonia, 357 (29.7%) of meningitis, 60 (5.0%) of cellulitis, and 61 (5.1%) of sepsis and other conditions. Hib was identified in 20.0% of children with meningitis and S. pneumoniae in 12.9%. The average annual incidence of Hib meningitis was 13.8 cases per 100 000 children under 5 years of age, and 32.4% of meningitides caused by Hib and 58.7% of S. pneumoniae meningitides occurred prior to 6 months of age. Case fatality rates were 14.1%, 37.0%, and 18.0%, respectively, for children with Hib, S. pneumoniae, and culture-negative and antigen-negative meningitis. Prior antibiotic therapy was common and was associated with significant reductions in CSF-culture-positive results for children with other evidence of Hib or S. pneumoniae meningitis. CONCLUSIONS: Improvements in case detection, culture methods, and latex agglutination for antigen detection in CSF resulted in identification of Hib and S. pneumoniae as important causes of severe disease in Guatemalan children. Using a cutoff of > 10 white blood cells per cubic millimeter in CSF would improve the sensitivity for detection of bacterial meningitis and help estimate the burden of bacterial meningitis in Guatemala and other developing countries.

Sanitary monitoring of an integrated system for the treatment of wastewaters from pig farming

OBJECTIVE: To assess the potential for contamination of wastewaters from pig farming. METHODS: Wastewaters from pig farming were stored in a tank. After 0, 30, 60, 90, and 120 days of hydraulic retention, they were added to lysimeters filled with argillaceous, sandy, or medium soil. Finally, these lysimeters were submitted to simulations of either a rainy season or a dry season. The number of colony-forming units (CFUs) of total coliforms, fecal coliforms, and fecal streptococci was measured in the effluents of the storage tank (for the various periods of hydraulic retention), in the percolate from the lysimeters, and in the three types of soil. The microbiological analyses were carried out using the membrane filter technique. The pH analyses were done potentiometrically. RESULTS: For the three microorganisms, the largest decrease in bacterial counts in the storage tanks occurred with 90 or 120 days of retention. There was a marked decrease in the bacterial count in the percolates of the three soils. For the three soil types the greatest reduction in bacterial counts was found in medium soil, due to its acidity (pH < 7.0). Hydraulic retention was not sufficient to ensure the sanitary adequacy of the wastewaters and their use for irrigation, given that fecal coliform values were above 1 000 CFU per 100 mL. Therefore, adding the residues to the soil was considered a second stage of treatment. CONCLUSIONS: The retention of wastewaters followed by adding them to soil was effective in minimizing the contaminating effect of pig farming residues. The storage time for wastewaters from pig farming could be decreased from 120 to 90 days.

A game as an educational strategy for the control of Aedes aegypti in Venezuelan schoolchildren Artículos

OBJECTIVE: To assess the value of a game known as Jugando en salud: dengue [Playing for health: dengue] as a teaching/learning tool leading to the incorporation of schoolchildren enrolled in secondary school in the control of Aedes aegypti and dengue prevention activities in the municipality of Girardot, Aragua state, Venezuela. METHODS: We performed a descriptive, quasi-experimental study based on field research carried out in 9 schools that were chosen by systematic random sampling among the 29 public schools in the municipality of Girardot, Aragua state, Venezuela, having three or more sixth-grade classrooms. In each school three workrooms were set up: in group no. 1 (210 students) the game was practiced three times a week for a total of 60 days, and the teacher was furnished with theoretical materials about dengue; in group no. 2 (196 students) only the theoretical materials that were given to the teacher were used, and in group no. 3 (215 students), which was the control group, the regular learning program established by the Ministry of Education was followed. Participating students were evaluated before and after each of the proposed programs by means of a questionnaire that was evaluated using a Likert scale. We calculated concentration and dispersion measures for the data obtained during the evaluations. Simple analysis of variance was used to compare the mean results obtained in the different classrooms and to detect significant differences among the various groups in terms of knowledge and skills before and after the proposed program. Scheffé's test was used to detect differences within groups. RESULTS: Six hundred twenty-one schoolchildren between the ages of 8 and 16 years (mean age: 11.8 years) participated in the study. Of the 210 students that took part in the game, 41% rated its acceptability as ''high'' and 45% as ''very high.'' The knowledge about dengue and the skills that were measured prior to following the prescribed program were lower (6.5 and 18.4 points, respectively) than those displayed in the final test (8.25 and 22.9 points, respectively; P < 0,05). There appeared to be better learning in the groups that used the game plus the theoretical materials (group no. 1), or that used just the theoretical materials (group no. 2), than in the control group (group no. 3). Students in workrooms 1 and 2 also appeared to acquire more skills than those in the control group (P < 0,05). CONCLUSIONS: The game was highly accepted among students enrolled in secondary school. It helped them acquire greater knowledge about dengue and to develop skills and abilities leading to their incorporation in dengue prevention activities in their respective communities. We recommend that the game be extended to all schools as a tool for strengthening the educational process and incorporating children in dengue control activities.

OBJECTIVE: To implement a training program for physicians and patients and assess its effectiveness in terms of patient compliance with the pulmonary tuberculosis treatment regimen in the border region of Chiapas, Mexico. METHODS: A controlled intervention study was performed with patients over 15 years of age who had pulmonary tuberculosis diagnosed by direct microscopy (bacilloscopy) between 1 February 2001 and 31 January 2002 in health units randomly selected in the border region of Chiapas, Mexico. The sample was made up of patients who sought consultation at 23 and 25 health units over that period (intervention and control group, respectively). The intervention group took part in a training program for health personnel in which the following were discussed: the social, cultural, and economic aspects of tuberculosis; the theoretical and practical underpinnings of the diagnosis and treatment of the illness, and the establishment of self-help groups. Self-help groups were also created for all patients at the 23 units where the intervention group sought consultation. All patients were given a short-term treatment regimen with isoniazid, rifampin, pyrazinamide, and ethambutol for a total of 25 weeks, until completing a total of 105 doses. Patient follow-up was extended through December 2003. The intervention and control groups were compared by means of the chi square test, and Student's t test was used to compare means. The relative risk of non-compliance (RR) was calculated along with 95% confidence intervals (95% CI). RESULTS: Eighty-seven patients participated in the study; 44 were exposed to the intervention, and 43 made up the control group. Compliance with treatment was considerably greater in the intervention group than in the control group (97.7% vs. 81.4%, respectively; RR = 1.20; 95% CI: 1.03 to 1.39; P = 0.0015). It was noted that physicians in the border region of Chiapas gear their activities toward curative medicine, rather than preventive medicine or understanding the social determinants of disease. CONCLUSIONS: As a result of the educational activities that were part of the intervention, there was an increase in the proportion of patients who complied with treatment. Health services can improve tuberculosis control in Chiapas with the resources that are available to them at present. Physicians should be taught to view health problems in Chiapas as part of an integral set of conditions, and efforts should be made to improve the doctor-patient relationship. Steps should also be taken to incorporate educational activities and community participation in health services in order to address public health problems in a comprehensive way.

Socioeconomic determinants of schistosomiasis in an urban area in the Northeast of Brazil Articles

OBJECTIVE: To identify and quantify the socioeconomic determinants of schistosomiasis in the urban section of São Lourenço da Mata, a town in the Northeast of Brazil. METHODS: A cross-sectional study was carried out in 1988 to measure the prevalence of schistosomiasis in São Lourenço da Mata among individuals aged 10-25 years and to estimate the socioeconomic characteristics of the households of those individuals. Household aggregation was tested. The data were analyzed on two levels, the family level and the individual level. On the family level we estimated the odds ratios for the association of schistosomiasis and socioeconomic variables related either to the head of the family or to the household. On the individual level we investigated if for the infected individuals there were differences in the intensity of infection (mean egg count) for the different levels of the socioeconomic variables. RESULTS: We found a significant degree of household aggregation of schistosomiasis (allowing for sex and area of residence (neighborhoods with similar socioeconomic conditions, according to census data)). In the analysis on the family level, better socioeconomic indicators for the place in the productive process (occupation, economic sector, and position in production of the head of the family, plus family income) and better socioeconomic indicators for patterns of consumption (level of education of the head of the family, type of housing, household possessions, water supply for the home, sanitation (that is, excreta collection), and family access to medical care) were all associated with a lower risk of schistosomiasis. The estimation of the probability of schistosomiasis for different levels of the socioeconomic variables showed a lower risk (0.072) for individuals whose households were at the top (best) levels of the indicators relative to the risk (0.715) for individuals whose households were at the baseline (lowest) levels of the indicators. Infected individuals whose families had better socioeconomic conditions had lower mean egg count values. CONCLUSIONS: Control measures that may have a long-term effect, such as improvements in the water supply and sanitation, should be strongly encouraged. The theoretical reduction that we found in the probability of being infected if water supply and sanitation were improved highlights the importance of these measures. Implementing them would have a more permanent effect on the control of schistosomiasis and would also result in other benefits to the population.

Risk factors for iron-deficiency anemia in children and adolescents with intestinal helminthic infections

OBJECTIVE: To investigate risk factors for iron-deficiency anemia in children and adolescents (7 to 17 years of age) with intestinal helminthic infections. METHODS: A cross-sectional study was carried out with 1 709 children and adolescents living in Jequié, a town in the state of Bahia, Brazil, who had mild to moderate infection by Schistosoma mansoni, Ascaris lumbricoides, Trichuris trichiura, or hookworms. We obtained data concerning hemoglobin levels (using a portable hemoglobinometer), dietary habits (24-hour dietary recall), parasitic infections (Kato-Katz method), sanitary conditions (water supply, sewage connection, garbage collection), housing conditions (type of construction, number of persons per room), income, and amount of schooling of the parents or guardians. The risk factors for anemia were studied based on a hierarchical model of causality. RESULTS: The prevalence of parasitic infection was 74.8% for T. trichiura, 63.0% for A. lumbricoides, 55.5% for S. mansoni, and 15.7% for hookworms. Among the children and adolescents studied 32.2% were anemic. After adjustment for confounding variables, the results of the multivariate analysis showed that the following variables were significantly associated with anemia: per capita family income below US$ 27 (equal to one fourth of the Brazilian minimum wage), male sex, age of 7 to 9 years, and inadequate intake of bioavailable iron. CONCLUSIONS: The initiatives to control anemia in the group at greatest risk, as identified in this study, should seek to increase the consumption of iron-rich foods, boost the bioavailability of the iron ingested, and improve socioenvironmental conditions.

The role of local governments in the fight against the scourge of AIDS Temas de Actualidad

The challenges imposed by HIV/AIDS in urban areas make it imperative to act at the local level. Local government agencies (LGAs) are closer to the victims of HIV/AIDS and are thus better able to undertake the needed actions. However, LGAs can succeed in the fight against HIV/AIDS only if they work closely with all levels of government and other local representatives of civil society that take part in the struggle against HIV/AIDS at the community level. In fact, the most obvious comparative advantage of LGAs may be their capacity for creating an atmosphere that is conducive to coordinating, directing, and undertaking local measures-both new and preexisting-against HIV/AIDS. Even with reduced support (financial or political), LGAs can achieve significant results in the fight against HIV/ AIDS by incorporating response measures against these conditions in the municipal agenda. It is precisely in order to help solve this complex situation that the World Bank has just published a book entitled Local Government Responses to HIV/AIDS: A Handbook. This text is intended for officials working for the mayor and members of local legislative bodies in charge of implementing sustainable and responsible measures against HIV/AIDS at the municipal level. Though it is hoped that each local government office will creatively follow the suggestions given in this manual, the theoretical framework and practical approach in it are a guarantee that applying them will lead to an improved ability to respond against HIV/AIDS on the part of local government agencies.